#include <iostream>
#include <string>

using namespace std;
typedef struct A
{
    int val_1;
    int val_2;

    int add()
    {
         return val_1 + val_2;
    }
}A;

class B
{
    public:
       int val_1;
       int val_2;

   int add()
    {
        return val_1 + val_2;
    }
};

int main(int argc, char const *argv[])
{
    A a;
    B b;
    a.val_1 = 10;
    a.val_2 =20;
    cout << a.add() << endl;
}